Leonhard ledeeer



UNITED STATES FATENT OFFICE.

LEONHARD LEDERER, OF MUNICH, GERMANY.

PROCESS OF MAKING AROMATIC OXYCARBON ACIDS.

SPECIFICATION forming part of Letters Patent No. 547,611, dated October8, 1895.

Application filed December 18, 1394. Serial No. 532,242. (Specimens) T0aZZ whom/it may concern.-

Be it known that I, LEONHARD LEDERER, a subject of the King of Bavaria,residing at Munich, in the Kingdom of Bavaria, Germany, have inventednew and useful Improvements in the Manufacture of Oxycarbon Acids of theAromatic Series, of which the following is a specification.

I have found that mixtures of the homologous phenols can be easilyseparated by convertin g them into the corresponding phenoxacetic acidsby means of chloracetic acid, in consequence of the diiferent degrees ofsolubility possessed by the said acids or of their salts.

I have discovered that the phenoxacetic acids, from which the phenolsare separated by heating with hydrochloric acid, can be converted intooxycarbon acids by melting with caustic soda or caustic potash. Theprocess is a very simple one 'and can be explained by the fact that thealkali separates the gly-- colrest: OH OOOH under simultaneous oxidationof the side groups.

As the crude phenols can be easily obtained, the new process isadmirably suited for the production of oxycarbon acids of the aromaticseries.

I. One part of ortho-cresoxacetic acid,

6 I Ne s (2)000H, (salicylic acid,) is separated.

II. One part carvacroxacetic acid,

(1 o.oH,.oooH e rn -(2)011 (o am.

and three parts caustic soda are heated to from 250 to 260 .centigradewith addition of a little water. The melt, after the passing away of theadded water and that combined with the alkali, becomes pasty and assumesa yellow color, the intensity of which gradually increases and passesover to orange. The melting process is finished when the reaction massforms an orange-brown mass of an almost dry powdery consistency. Theaqueous solution of the melt is decomposed by means of dilute sulfuricacid.

III. One part thymoxacetic acid,

(1)OCI-I .OOOI-I Q 7 and three parts caustic soda are heated to from 240to 250 centigrade with addition of a little Water. The mixture, whichafter driving off the water is almost dry, becomes liquid and shortlyafter thickens with anorange coloration. As soon as the melt shows adeep orange-red color, the reaction is finished. If the melting processis continued until a brown-red coloration is obtained, there will beproduced mainly oxyterephthalic acid,

(1)OH O H (5)OOOII (2)0OOH.

or mono=oxybenzoic acid,

The melt mixed with water is decomposed by dilute mineral acids.

IV. One part creosoxacetic acid,

(1)o.cH,.ooon H (2)OOH or eugenoxacetic acid,

from 230 to 250 centigrade, with addition of a little water. Thereaction mass first becomes liquid, then pasty, assuming a yellow color,which rapidly becomes an orange color. After the melt has again becomeliquid it reassnmes the pasty form, and the reaction is finished whenthe mass becomes a dry powder.

The decomposition of the melt when mixed with water is effected, as inall other cases, by means of dilute mineral acids.

The above described process can be carried [0 out either at atmosphericor higher pressure.

Vhat I claim is-

